Objectives: To compare the ability of the commonly used Women's Health Initiative (WHI) and Cardiovascular Health Study (CHS) frailty phenotypes to predict falls, hip fracture, and death in WHI Clinical Trial participants aged 65 and older. Design: Longitudinal cohort study. Setting: WHI Clinical Trial. Participants: Participants with data for WHI and CHS frailty phenotypes (N = 3,558). Measurements: Frailty was operationally defined in the CHS as the presence of three or more of weight loss, poor energy, weakness, slowness, and low physical activity. WHI operationalized frailty similarly but with the RAND-36 physical function scale substituted for slowness and weakness (RAND-36 physical function scale score <13 = 2 points, 13–78 = 1 point, >78 = 0 points). Frailty was defined as a summary score of 3 or greater, prefrailty as a score of 2 or 1, and nonfrailty as a score of 0. Outcomes were modeled using Cox regression. Harrell C-statistics were compared for models containing alternative instruments. Results: Approximately 5% of participants were frail based on the CHS or WHI phenotype. The WHI frailty phenotype was associated with higher rates of falls (hazard ratio (HR) = 1.48, P =.003), hip fracture (HR = 1.87, P =.04), and death (HR = 2.32, P <.001). Comparable HRs in CHS-phenotype frail women were 1.32 (P =.04), 1.08 (P =.83), and 1.91 (P <.001), respectively. Harrell C-statistics revealed marked but insignificant differences in predicting abilities between CHS and WHI phenotype models (P >.50 for all). Conclusion: The WHI phenotype, which does not require direct measurements of physical performance, might offer a practical advantage for epidemiological and clinical needs.
Bibliographical noteFunding Information:
The authors thank the WHI investigators and staff for their dedication and the study participants for making the program possible. A listing of WHI investigators can be found at https://cleo.whi.org/researchers/Documents%20%20Write%20a%20Paper/WHI%20Investigator%20Short%20List.pdf. The WHI program is funded by the National Heart, Lung and Blood Institute, National Institutes of Health, U.S. Department of Health and Human Services through Contracts N01WH22110, 24152, 32100–2, 32105–6, 32108–9, 32111–13, 32115, 32118–32119, 32122, 42107–26, 42129–32, and 44221. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. Author Contributions: Drs. Zaslavsky and Zelber Sagi had full access to all of the data used in the study and take responsibility for the integrity of the data and accuracy of data analysis. Zaslavsky, Woods, Zelber-Sagi: study concept, design, interpretation of data, preparation of manuscript. Zaslavsky, Zelber-Sagi, Woods: data analysis, visualization. Gray, LaCroix, Brunner, Wallace, O'Sullivan, Cochrane: preparation of manuscript. Sponsor's Role: The funding agencies had no role in the design and conduct of this study, the analysis or interpretation of the data, or the preparation of the manuscript.
© 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society
- hip fracture
- predictive ability
ASJC Scopus subject areas
- Geriatrics and Gerontology